Turbine-engine.



M. A. PRATT.

TURBINE ENGINE.

APPLICATION FILED MAR. 2l, 1916.

Patented Feb. 13, 191'?.

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M. A. PRATT.

TURBINE ENGINE.

APPLICATION FILED MAR. 21. IsIs.

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@Horne/1j MILFORD A. PRATT, F LEBANON, INDIANA.

TURBINE-ENGIN E.

Appli-cation led March 21, 1916.

To altwwmz't may concern:

Be 1t known that I, MILFORD A. PRATT, a

citizen of the United States, residing at Lebanon, in the county ofBoone and State of indiana, have invented new and useful Vimprovementsin Turbine-Engines, of which the following is a specification.

This invention relates to turbine engines designed to be operated by airor other fluid pressure, and particularly adapted for driving theconcentrically mounted propellers of torpedoes, and for other similarpurposes;

One object of the invention is to provide a. turbine engine wherein thecasing and rotor are provided with coperating vanes or fins constructedand arranged to receive the impact and utilize the expansive force ofthe iiuid in such a way as to secure a driving action while obtaining abalancing of pressures so as to avoid undue endwise thrust in eitherdirection of or upon the engine shaft. Y

A further object of the invention is to provide an engine of thecharacter described wherein the casing constitutes an outer rotor andthe blades or vanes'upon the perimeter of the casing and periphery ofthe rotor proper are formed to direct the fluid laterally in roppositedirections simultaneously against the vanes of both rotors to drive thesame in opposite directions while diminishing endwise thrust pressurestothe minimum degree.

A still further object of the invention is to provide an engine of thecharacter described wherein the vanes upon the surfaces of the.coperating parts above referred to are arranged so as to provideexpansion chambers of novel construction, formation and arrangementwhereby the free eXpansion of the fluid is permitted and obtained forthe utilization of the full forces thereof and for securing a -free andunrestricted discharge of the spent Huid through the eX- haust withoutundue resistance or back -pressure.

A still further object of the invention is to provide an engine of thecharacter described embodying novel forms of fins or vanes for thepurposes described, a novel `construction and arrangement of intake andexhaust passages, a novel mode of constructing and mounting the-vanecarrying rings, and novel means for connecting the inner and outerrotors for operationl at a uniform Specification of Letters atent.

Patented Feb. 13, 191% Serial No. 85,679.

speed and for transmitting motion therefrom to the parts to be driven.

With these and other objects in view, the invention consists of thefeatures of construction, combination and arrangement of partshereinafter fully described and claimed, reference being had to theaccompanying drawings in which z* Figure 1 is a central verticallongitudinal section through a turbine engine constructed in accordancewith my invention.

Fig. 2 is a vertical transverse section .through the engine on the line2-2 of Fig. 1.

`Fig. 3 is a vertical transverse section through the engine on the line3 3 of Fig. 1,

Figs. 1- and 5 are side views showing one of the outer and one of theinner vane carrying rings respectively applied to the casing and innerrotor or piston.

Fig. 6 is a diagrammatic plan view showing the arrangement of the vanesupon the rotating elements of the engine at atime when adjacent vanesregister with each other. Y

Referring to the drawings, 1 and 2 respectively designate the ends ofthe engine shaft which are journaled in suitable antifriction bearings 3and l1 and are suitably fixed to the ends of an inner rotor 5 arrangedwithin a casing or outer rotor 6 having hollow end shaft sections 7 and8 mounted to respectively revolve upon the said engine shaft sections 1and 2.

The inner rotor 5 comprises a cylindrical body `9 provided at itsopposite ends with sets of radial spokes 10 and 11 and having a Centralset or series of spirally disposed spokes `12, the main shaft section 1being suitably connected with the spokes 10 and 12, while the main shaftsection 2 is suitably connected with the spokes 11. The spokes areproperly spaced apart to provide exhaust passages 13 communicating withan exhaust chamber 1li formed within the body of the rotor 5 and whichis in unrestricted communication with an exhaust passage 15 in the mainshaft section 2, the shaft section 1 being provided with an admission orfeed passage 16 communicating with the Huid supply pipe 17.

The chamber 5 is in open communication with expansion chambers 18provided bel tween the ends of the inner and outer rotors, while thefeed passage 16 connects at its inner end with fluid delivery ducts orchannels 19 formed in the spira-l or serpentine shaped central spokes12. These ducts 19 are accordingly also of serpentine or spiral shapeand open at their outer ends through a central peripheral flange orannulus 20 upon the periphery of the inner rotor, whereby the fluid isdischarged between the working surfaces of the inner and outer rotorsfor imparting motion thereto.

Provided upon the periphery of the rotor are blades, fins or vanes 2l,and provided upon the perimeter of the casing or outer rotor (5 arecooperating blades, fins or vanes Q2, all except the central series ofvanes 21, which are provided upon the flange 20, being carried by ringskeyed, as shown at 2l, to the periphery of the rotor 5 and clamped inposition against the central flange 20 by outer threaded pairs ofretaining rings 25. The vanes 22 are similarly carried by rings 2G whichare keyed to the perimeter of the rotor 6, as at 27, and are held orclamped in position between the removable end headsQS of said rotor 6,which are provided with the hollow shaft sections 7 and 8.

It will be observed that the vanos 2l and v 22 upon the series of ringson the inner and outer rotors are ar anged in alternation with eachotherfrom the center toward the opposite ends of the rotors, and that thealternating vanos are curved on arcs in different directions so as tocollectively present Aa fluted or corrugated surface in a directiontransversely to the axis of the motorwhen the vanes come into transversealinement or registration. Hence it will be apparent that the sets ofvanes provide zigzag channels between them at right angles `to the axisof rotation of the rotors for the travel of the fluid laterally andlongitudinally in opposite directions, and that the fluid is thus causedto exert its impact as well as its ex-V pansive `force simultaneouslyupon the sets of vanes in opposite directions, thereby driving the rotor5 in one direction and the rotor 6 in the opposite direction.` By thisaction and the escape of the `[luid laterally as well aslongitudinallyin opposite directions in its courseof travel, it will be evident thatthe working thrust will be taken up entirely and expended laterally bythe rotor vanos, thus entirely preventing reducing end thrust upon theshaft sections tothe minimum.

Itl will be observed further that therings Q3 are of lthe same diameterat the center of the'rotor 5 and for like distances on `opposite sidesof thek central flange 20, but be- .vond these points and between thesame and the ends of the rotorprogressively decrease in diameter, `thusproviding a `central annular Huid channel 29 for the dow of the.

fluid during .its impact action and expansion chambers 30 which.progressively increasein area and depth longitudinally and radiallytoward the spaces or chambers 1S, allowing the fluid to expand freelyand easily and so as to avoid any tendency to back pressure orfrictional resistance liable to cause slippage and diminish power andspeed. The fluid after exerting its working forces may thereforedischarge into the spaces l8 and through the passages at the ends of theinner rotor into the chamber 5 and out through the exhaust passage l5 inthe main shaft section 5 are preferably made ihn-shaped to serve aspropeller blades and thus create a suction to promote the discharge ofthe exhaust.

lVhile the engine may be employed for general use for driving varioustypes or kinds of machines or elements to be driven, it is particularlyintended for use in driving the concentric shafts of oppositely rotatingpropellers, such as of a torpedo or for analo gous purposes, and it istherefore desirable to have a. balanced action of the engine and theoperation of the rotors at uniform speed. To this end the shaft sectionsl and t are provided with gear elements 31 and 32 which mesh with anintervening equalizing gear element 33 suitably journaled on the bearingelement 3, so that the rotors will be caused to have a balanced rotaryaction and to turn at equivalent'speeds. Suitable means may be providedfor transmitting motion from the rotors to the parts torbe driven, andin the present instance I have shown for this purpose gear elements 3iand 35 mounted upon the shaft sections 2 and '8 and from which motionmay be trans-V mitted through suitable gearing (not shown) to thepropeller shafts or other parts to be driven for driving the same inopposite directions at corresponding speeds.

lVhile the construction shown and described is preferred, it will ofcourse be understood that modifications within the scope of the`appended claims may be made without departing from the spirit orsacrificing any of the advantages of the invention. It is also to `beunderstood that whilethe engine is expressly designed for `the use ofcompressed air asv the impelling agent, any other suitable motive fluidmay be employed.

I claim 1. An elastic fluid turbine including inner and-outer rotorsprovided with cooperating vanes, the inner rotor `consisting of a.hollow body forming an exhaust chamber communicating with the spacesbetween the vanes, and means for supplying a motive fluid to act uponthe vanes.

Q. An elastic iiuid turbine including inner and outer rotors providedwith cooperating Yanes, an inner rotor'consisting of a 'hollow bodyforming an exhaust chamber, communicating with the spaces between thevvanes, propeller blades upon said inner rotor forniing a suction and'discharge veneto promote The end spokes 'llof the rotor.

nemica the discharge of the exhaust, and means for supplying a motivefluid to act upon the vanes.

3. An elastic fluid turbine including inner and outer concentricallymounted rotors provided with coperating vanes, the inner rotorconsisting of a hollow body forming an exhaust chamber and arranged toprovide exhaust passages at the ends of the outer rotor communicatingtherewith and with the spaces between the vanes, means extending throughsaid inner rotor for supplying a motive fluid to the vanes, and meanscommunicating with the exhaust chamber of said rotor for the dischargeof the exhaust therefrom.

ll. An elastic fluid turbine including a casing, a rotor arranged withinthe casing and comprising a hollow body forming an internal exhaustchamber and having spokes extending to the center of its periphery andprovided with fluid supply ducts, said rotor being of less length thanthe casing to provide expansion spaces at the ends of the casing incommunication with said expansion chamber, and vanes upon the peripheral surfaces of the casing and rotor.

5. An elastic fluid turbine including a main shaft having hollowadmission and exhaust sections, a casing having hollow shaft portionsmounted to turn upon the said sections of the main shaft, a rotorarranged within the casing and comprising a hollow body forming aninternal exhaust chamber and having spokes extending to the center ofits periphery and provided with fluid supply ducts communicating withthe bore of the admission section of the shaft, said rotor being of lesslength than the casing to provide expansion spaces at the ends of thecasing in communication with said expansion chamber, and said chamberbeing in communication with the exhaust section of the shaft, and vanesupon the peripheral surfaces of the casing and rotor.

6. An elastic fluid turbine including inner and outer rotors providedwith coperating vanes, the inner rotor consisting of a hollow bodyforming an exhaust chamber and provided with propeller blades at theends thereof to form a suction to promote the discharge of the exhaust,and means for supplying a motive fluid to act upon the vanes.

In testimony whereof I allix my signature in presence of two witnesses.

MILFORD A. PRATT. lVitnesses:

Morir L. Bufrormii, A. A. WILLmMsoN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patente, Washington, D. C.

